Endoluminal access devices and related methods of use

ABSTRACT

An endoluminal access system for accessing a body lumen, comprises a guide track which, when in an operative position, extends through a body lumen to a desired location therewithin and a modular device selectively coupleable to the guide track, the modular device including a drive mechanism for engaging the guide track to move the modular device along the guide track within the body lumen. A method of resecting tissue from a site within a body comprises the steps of inserting a guide track to a desired location within the body lumen, coupling a modular device to a proximal end of the guide track and actuating a motor mounted within the modular device to drive the modular device distally along the guide track to the site, drawing tissue at the site into the modular device in combination with the steps of coupling together a portion of tissue adjacent to the site, resecting the tissue from the site and actuating the motor to drive the modular device proximally to withdraw the modular device from the body lumen.

FIELD OF THE INVENTION

The present invention relates to the field of endoluminal accessdevices, and more particularly to endoluminal access devices driven bymechanical, electrical, and other like devices, and related methods ofusing such devices.

BACKGROUND OF THE INVENTION

Many endoluminal procedures are performed each year. Endoluminalprocedures take place within tubes or lumens of the human body, such asvascular, gastrointestinal, or air exchange lumens, and generallyinvolve the diagnosis and/or treatment of diseases and/or debilitatingconditions. Endoluminal procedures generally involve use of a rigid orflexible tube such as an endoscope, which may be introduced into thehuman body through a body orifice, such as the mouth or rectum orthrough an incision. Endoscopes allow users to view intended internaltreatment sites and may provide one or more working channels, orpathways, to the treatment site.

Endoscopes may be manually steered or positioned through the body untilthe endoscope is properly positioned. For some devices used to removetumors and polyps, e.g., full thickness resection devices (FTRDs),accurate positioning is important to successful use.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an endoluminal accesssystem for accessing a body lumen, comprising a guide track which, whenin an operative position, extends through a body lumen to a desiredlocation therewithin and a modular device selectively coupleable to theguide track, the modular device including a drive mechanism for engagingthe guide track to move the modular device along the guide track withinthe body lumen.

The present invention is further directed to a method of resectingtissue from a site within a body comprising the steps of inserting aguide track to a desired location within the body lumen, coupling amodular device to a proximal end of the guide track and actuating amotor mounted within the modular device to drive the modular devicedistally along the guide track to the site, drawing tissue at the siteinto the modular device in combination with the steps of couplingtogether a portion of tissue adjacent to the site, resecting the tissuefrom the site and actuating the motor to drive the modular deviceproximally to withdraw the modular device from the body lumen.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of theinvention and together with the description, serve to explain theprinciples of the invention. In the drawings,

FIG. 1 is a perspective view of an access device according to anembodiment of the present invention;

FIG. 2 is a partial cross-section view of the access device of FIG. 1;

FIG. 3 is a cross-section view of another embodiment of an access deviceaccording to the present invention;

FIG. 4 is a cross-section view of a further embodiment of an accessdevice according to the present invention;

FIG. 5A is a side view of a still further embodiment of an access deviceof the present invention in a first configuration;

FIG. 5B is a side view of the device of FIG. 5A in a secondconfiguration;

FIG. 5C is a side view of the device of FIG. 5A in a thirdconfiguration;

FIG. 5D is a side view of the device of FIG. 5A in a fourthconfiguration;

FIG. 6A is a perspective view of an external drive shaft according to anembodiment of the present invention;

FIG. 6B is a cross-section view of the drive shaft of FIG. 6A;

FIG. 6C shows a side view of an additional embodiment of an accessdevice according to the present invention including a drive shaft asshown in FIGS. 6A and 6B;

FIG. 7A is a cross-section view of a proximal portion of a modulardevice for use in the access device of FIGS. 5A-5D;

FIG. 7B is a cross-section view of a proximal portion of the modulardevice of FIG. 7A taken at line B-B of FIG. 7A;

FIG. 7C is a cross-section view of the proximal portion of the modulardevice of FIG. 7 taken at line C-C of FIG. 7A;

FIG. 8A is a cross-section view of a distal portion of the modulardevice of FIG. 7A; and

FIG. 8B is a cross-section of the distal portion of the modular deviceof FIG. 7A taken at line B-B of FIG. 8A.

DETAILED DESCRIPTION

Reference will now be made in detail to the present exemplaryembodiments of the invention, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

According to the present invention, an endoluminal access systemincludes a modular device containing tools for performing an internalprocedure or treatment. The modular device may be moved within a bodylumen, for example, along a guidewire inserted thereinto without anendoscope. The modular device may optionally include an internal or anexternal power source driving the modular device along the guidewire.

The use of a guidewire to direct the device to the treatment site ratherthan an endoscope may make access to internal treatment sites less timeconsuming and may reduce trauma to the body tissues associated with theinsertion of an endoscope. A guidewire may be inserted into the bodylumen and directed to the treatment site by methods known in the art.The modular device may then be slidably coupled to the guidewire andmoved therealong to the treatment site. If the modular device is coupledto a powered drive mechanism, there will be no need for an operator topush or force the modular device into the body lumen. Bodytissues/lumens may be required give way as the modular device movesalong the guidewire. However, these tissue do not remain in a stretchedor expanded state as long as is required for an endoscope which willextend along the entire distance from the point at which the endoscopeenters the body to the treatment site. In contrast, only that portion ofthe tissue currently in contact with the modular device may be impactedwhile the rest of the tissue between the treatment site and the openingto the body lumen will be occupied only by the small diameter guidewire. Thus, trauma to surrounding tissue may be reduced. In addition,depending on the number and nature of the tools required for a certainprocedure, the modular device employed may be smaller in diameter than astandard endoscope. This may further reduce trauma to surroundingtissue.

In addition, as described below, the driving mechanism of the modulardevice and an optional viewing device, make it is possible to accuratelyposition the modular device. The accuracy in positioning may reduce thetime required for the treatment and may also reduce risk of erroneouslytreating the wrong area.

According to the present invention and as embodied in FIG. 1, anendoluminal modular access system 100 is provided. System 100 maygenerally include a modular device 110, a track 120 for guiding/movingthe modular device 110, and a drive mechanism 112 for driving themodular device 110 along the track 120. Each of these general portionsof system 100 will be described in detail below.

As embodied herein and shown in FIG. 1, a modular device 110 fortraveling within a body lumen 103 may vary in size and shape dependentupon the size and type of tools required for a given procedure andcontained therewithin and/or the size and shape of the body lumen inwhich it is to be used. The exterior of modular device 110 mayoptionally include a hydrophilic coating to facilitate passage throughthe body lumen 103 and may preferably have rounded edges to facilitatemovement within the body lumen 103. Modular device 110 also includesholes 117 a, 117 b formed in the proximal and distal ends, respectively,of the modular device 110 for receiving the guide track 120 as describedin detail below.

FIG. 2 shows an embodiment of a drive mechanism 112 which may beprovided in modular device 110. As shown in FIG. 2, the drive mechanism112 includes a motor 115 engaging a guide track 120. Motor 115 iscontained within modular device 110 and may be connected via a cable 135to an external power source and control box 140. Cable 135 extends frommodular device 110 to the power source and control box 140 which islocated externally of the patient. In this embodiment, motor 115 isconnected to gear wheels 130 so that gear wheels 130 rotate when poweredby the motor 115. Control box 140 enables a user to determine adirection of rotation of gear wheels 130 and may also allow a user tocontrol a speed of rotation thereof. When rotated in a first direction,gear wheels 130 draw the modular device 110 distally along the guidetrack 120 into the lumen of the body of the patient and away from theoperator. When rotated in the second direction, the gear wheels 130 drawthe modular device 110 proximally along the guide track 120 toward theexternal opening of the lumen of the patient and toward the operator.

Those skilled in the art will understand that various known suitablesources of power and various known suitable devices for controlling thesource of power, movement and operation of the modular device 110 may beemployed. For example, the power source may be a battery device, or asource of air or hydraulic pressure such as a pneumatic or hydraulicpump. In addition, although FIG. 2 shows the use of three gear wheels130, those skilled in the art will understand that any suitable numberand type of gear wheels or other like device may be employed to griptrack 120 and move the modular device 110 therealong. For example, acontinuous belt may frictionally engage the guide track 120 so thatrotation of the belt drives the modular device 110 therealong. Theinvention is not to be limited to any particular power supply orcontroller, or drive mechanism type.

As embodied herein and shown in FIGS. 1 and 2, modular device 110 movesalong a guide track 120. Guide track 120 may be, for example, a straightguidewire or shaft, a catheter, a coiled guidewire or metal shaft, orany like device. Guide track 120 is intended to be inserted into thelumen 103 of the patient toward the desired treatment site prior to theinsertion of the modular device 110 using known techniques. The guidetrack 120 may then optionally be anchored within the lumen at a desiredlocation relative to the treatment site. A proximal end of the guidetrack 120 is then inserted into the hole 117 b and the modular device110 is driven distally along the guide track 120 until the proximal endof the guide track 120 exits the hole 117 a. Further advancing themodular device 110 distally along the guide track 120, the operator thenguides the modular device 110 into the opening to the body lumen andadvances the modular device 110 distally to the treatment site.

In the embodiment shown in FIG. 2, gear wheels 130 engage guide track120, which may be formed, for example, as a straight guidewire orflexible shaft. Gear wheels 130 are powered by the motor 115 which ispowered by the external power supply. If a forward direction is selectedon the control box, the gear wheels 130 will rotate and grip track 120such that modular device 110 moves in a forward, distal direction alongtrack 120. If a reverse direction is selected, the modular device 110moves in a rearward, proximal direction along track 120. In addition todirection control, control of the speed of the modular device 110 may beprovided so that, for example, modular device 110 can be more quicklymoved to the treatment site, and have its position fine-tuned at lesserspeeds. The speed of modular device 110 may be dictated byconsiderations of safety to the patient and the capability of the powersource and drive device.

FIG. 3 shows another embodiment of a drive mechanism 112 provided inmodular device 110. In this embodiment, an electric motor 115 is againprovided inside modular device 110. Those skilled in the art willunderstand that the motors employed in connection with any of theembodiments of this invention need not be electric motors.Alternatively, as would be understood by those of skill in the art, thefunctions of all of these motors may be provided by fluid powered motorssuch as air/hydraulic motors. Such motors may be run in two directionsby, for example, including two separate fluid supply lines, one of whichis to be engaged for a first direction of rotation of the motor withengagement of the second operating the motor in the opposite direction.Motor 115 is powered as described above, and is connected to a gear set130 a. Gear set 130 a is positioned within modular device 110 to engageguide track 120 a, which is embodied as a coiled guidewire or shaft. Atleast one portion of modular device 110 which contacts and sits on guidetrack 120 a includes a threaded portion to allow modular device 110 tomove along coiled guide track 120 a. The threaded portion is preferablya threaded hole 117 b in an end of modular device 110 which intermesheswith the coils of track 120 a. Gear set 130 a engages the coiled guidetrack 120 a, and when powered, gear set 130 a moves along the coils ofguide track 120 a to move modular device 110 in either a forward(distal) or reverse (proximal) direction.

FIG. 4 shows a further embodiment of a drive mechanism 112 provided inmodular device 110. In this embodiment, a n electric motor 115 isprovided inside modular device 110. The motor 115 may be powered asdescribed above, and includes a rotor 132 and stator 134 arrangement, aswould be understood by those of skill in the art. The rotor 132 ispositioned within the stator portion 134 and includes a central threadedportion. Rotor 132 is positioned within the modular device 110 to engageand rotate about guide track 120 b, which is embodied as a coiledguidewire or shaft. As shown in FIG. 4, the coils of the guide track 120b provide a substantially helical threaded surface which is engaged bythe corresponding threaded portions 111 a, 111 b of the lumen extendingthrough the modular device 110 through which the guide track 120 bpasses are formed at the proximal and distal ends of the modular device110. Contact between these threaded potions 111 a, 111 b and the guidetrack 120 b as the modular device 110 is rotated by the electric motor115 moves the modular device proximally or distally therealong dependingon the direction of rotation. Those skilled in the art will understandthat the rotor 132 may optionally be nonrotatably coupled to thethreaded portions 111 a, 111 b while a radially outer portion of themodular device 110 is rotatably coupled to the rotor 132 and thethreaded portions 111 a, 111 b so that this radially outer portion maymaintain a substantially constant angular orientation relative to theguide track 120 b as the modular device 110 is moved therealong.

Furthermore, as shown in FIGS. 5A-5D, the endoluminal modular accesssystem 100 may also include an anchor module 150 to anchor a portion ofthe guide track 120 b (e.g., the distal end thereof) at a desiredlocation within the body lumen 103 so that the modular device can bemore easily advanced along guide track 120 b. The anchor module 150 maypreferably contain a motor (e.g., a servo screw motor) (not shown)which, when powered, moves the anchor module 150 along the guide track120 b in a manner similar to that described in regard to the motion ofthe modular device 110 along the guide track 120. Furthermore, thoseskilled in the art will understand that any suitable motor or other likedrive device may be used to power the anchor module 150. For example,the anchor module 150 may utilize any of the drive devices andactivators described in connection with the modular devices 110 of thisinvention. The anchor module 150 preferably has rounded edges tominimize trauma to body tissue and to ease movement of the anchor module150 through the body lumen. An anchoring extendible member 152 isprovided on the anchor module 150 which may be configured in a firstradially compressed state for insertion and retraction from thepatient's body and a second radially expanded state in which theextendible member 152 contacts the wall of the body lumen 103 to anchoritself and the guide track 120 in place. Those skilled in the art willunderstand that the expandable member may be an extendible cage or armor, as shown in FIGS. 5A-5D, a balloon. Furthermore, those of skill inthe art will understand that the anchoring module 140 may include morethan one extendible member 152 to aid in stabilizing the anchor themodule 150 in position. In use, the anchor module 150 is preferablydeployed when the distal end of the guide track 120 is brought to thedesired location within the body lumen 103 prior to the insertion of themodular device 110 into the body lumen. The motor within the anchormodule 150 may engage the guide track 120 b in any manner similar tothose described in regard to the modular device 110 (e.g., a gear orbelt drive, threaded holes engaging a helical thread of the guide track120, etc.).

Once at the distal end of the track 120 b has reached the desiredlocation within the body lumen 103, the extendible member 152, isactuated. For example, for a balloon extendible member 152, the operatorsupplies fluid to the balloon via the tube 156 to expand the balloonuntil it contacts the wall of the body lumen 103. To do this, theoperator connects the tube 156 to a suitable source of fluid preferablyexternal to the patient's body. The balloon of extendible member 152expands until it contacts and pushes against the walls of the bodylumen. Thus, extendible member 152 anchors itself within the body lumenand because it is anchored, it stabilizes the track 120 b for themodular device 110.

In this preferred embodiment as shown in FIG. 5D, the modular device 110may also include an extendible member 154, (e.g., a positioning balloon)for stabilizing the position of the module device 110 during theprocedure to enable optimal use of the tools contained therein. Theextendible member 154 may be arranged such that, when in the extendedconfiguration, pushes the modular device 110 into contact with one sideof the lumen 103 (e.g., the side of the lumen on which the tissue to betreated is located). The extendible member 154 is supplied with aninflation fluid (e.g., air or saline) via an inflation lumen (not shown)which is preferably separate from that used to inflate from the tube 156which is used to inflate the balloon extendible member 152.

In a further embodiment of an endoluminal modular access system, themodular device 210 may be a full thickness resection device (FTRD). Thefunction of an FTRD is to remove a full thickness section of tissue froman organ and reseal the opening created through the resection. The FTRDmodular device 210 is shown in FIGS. 5C and 5D and FIGS. 7 and 8.

FIG. 7A shows a cross-section of a proximal portion of the FTRD modulardevice 210. As can be seen in FIG. 7A, FTRD modular device 210 includesan outer casing 202, and a central motor 215. Outer casing 202 ispreferably smooth, and formed of a biocompatible material such as abiocompatible plastic or metal, as would be understood by those of skillin the art. Furthermore, the outer casing 202 may include a hydrophiliccoating. The outer casing 202 is preferably oval or circular incross-section with blunt, rounded ends. Other shapes such as, forexample, a rectangular cross-section with rounded corners may also beused. The size of the outer casing 202 is preferably between 2 and 10 cmin length with a circumference (or perimeter) of between 3 and 19 cm. Aswould be understood by those of skill in the art, the size of the outercasing 202 may vary based upon the type and size of the tools requiredfor a particular procedure and which are contained within the outercasing 202. Motor 215 may preferably be a direct current electric motorwhich may be driven in two directions. Motor 215 includes outer windings215 a which are stationary and attached to outer casing 202 and anarmature formed as a sleeve 215 b having a central lumen extendingtherethrough. A guide track, e.g., in the form of a catheter 220 may beslidably received in the central lumen of the armature sleeve 215 b withthe armature sleeve 215 b rotating thereabout when the motor 215 isdriven to move the FTRD modular device 210 along the catheter 220 viathe drive mechanism described below.

As shown in FIGS. 7A and 8A, the drive mechanism 112 provided in theFTRD modular device 210 includes proximal and distal sets of rollergears 230 a, 230 b positioned around the catheter 220 proximally anddistally of the armature sleeve 215 b, respectively. When in anunpowered state, roller gears 230 a, 230 b are moved out of engagementwith the catheter 220. However, when power is supplied to the motor 215,the roller gears 230 a, 230 b are firmly pressed against the catheter220 to engage catheter 220 so that rotation of the roller gears 230 aand 230 b draws the FTRD modular device 210 along the catheter 220either distally or proximally, depending on a direction of rotation ofthe motor 215.

Roller gears 230 a, 230 b are powered by armature sleeve 215 b througharmature sleeve gear 215 c and roller takeoff gear 232. Roller takeoffgear 232 is connected to roller gears 230 a, 230 b through a shaft 234.Roller gears 230 a, 230 b are moved into and out of contact with thecatheter 220 by pressers 240 which are moved radially inward when themotor 215 is powered contact the roller gears 230 a, 230 b to press theroller gears 230 a, 230 b into contact with the catheter 220. When poweris withdrawn from the motor 215, the pressers 240 are moved radiallyoutward to remove the inward pressure on the roller gears 230 a, 230 b.The roller gears 230 a, 230 b are biased radially outward by a biasingmember (not shown) so that, when the pressers 240 are moved out ofcontact therewith, the roller gears 230 a, 230 b are automaticallywithdrawn from contact with the catheter 220. Pressers 240 are shiftedradially by longitudinal pressers 245 which are moved longitudinallyinto and out of contact with the pressers 240 by an electrically poweredlinear transducer 247. As would be understood by those of skill in theart, transducer 247 may be an electrically charged magnetic solenoidconfigured to apply linear force to the longitudinal pressers 245.Alternatively, transducer 247 may be replaced by a hydraulic piston.

As embodied herein and shown in FIGS. 7A and 8A, FTRD modular device 210includes a grabbing element 260 having end grippers 262 for grabbing aselected tissue sample and pull the tissue into a tissue receivingchamber 264 a formed within the FTRD modular device 210. Grabbingelement 260 is mechanically controlled by manipulation of an actuatorwhich remains external to the patient and which is connected to aproximal end of grabbing element 260 by, for example, a control cable,flexible drive shaft, hydraulic line, as would be understood by those ofskill in the art. Furthermore, any of various known suitable actuatorsmay be used to allow the operator to control the grabbing element 260.In an alternative embodiment, grabbing element 260 may be replaced witha vacuum grabber for drawing the selected tissue into the tissuereceiving chamber 264 a as would be understood by those of skill in theart.

As embodied herein and shown in FIGS. 7A and 8A, a cutting element 266,which may, for example, be in the form of a curved blade having acutting surface extending at an angle relative to a longitudinal axisthe FTRD modular device 210, in an operative configuration extends intothe tissue receiving chamber 264 a. Cutting element 266 is operatedafter the selected portion of tissue has been stapled as described belowto cut the selected portion of tissue away from the body lumen so thatit may be retained within the tissue receiving chamber 264 a. A lineartransducer 272 engages and disengages a cutter engaging element 270.After FTRD modular device 210 has reached a desired position, theactuator 247 is released to disengage roller gears 230 a, 230 b therebypreventing further movement of the FTRD modular device 210 along thecatheter 220.

A window formed in the outer casing 202 is covered by clamping element274. The window may then be opened, as shown in FIG. 8A, by activating alinear transducer 276 which is coupled to the clamping element 274. Thelinear transducer 276 may be controlled by, for example, an electricsolenoid or fluid powered cylinder as would be understood by those ofskill in the art. A selected portion of the tissue is drawn into thetissue receiving chamber 264 a using the grabbing element 260 andoperator controls the linear transducer 276 to move the clamping element274 into the closed position adjacent the anvil 264 to close the windowand clamp the tissue between the anvil 264 and the clamping element 274.The anvil 264 is driven by a hammer 280 to form the staples, asdescribed below to staple to tissue, as described below and, after thisstapling has been completed, the actuator 272 is powered and a drivetrain is established between drive gears 215D, an idler gear 217 on theend of actuator 272, and cutter gear 270 to begin movement of thecutting element 266 to sever the tissue radially within the stapledtissue. As the connection between the roller gears 230 a, 230 b has beenremoved, the motor 215 may be driven to actuate the cutting element 266without driving the FTRD modular device along the catheter 220.

When linear transducer 272 engages the cutter engaging element 270, acutter sleeve armature gear 215D is activated by cutter engaging element270. Cutter sleeve armature gear 215D, in turn, causes rotation of acutter take up gear 268 which rotates cutting element 266, causing it tocut the selected tissue sample. Structural members extend between thetransducers 247, 276 to support them and the tissue receiving chamber264 a extends between an anvil 264 (which forms staples) and theclamping element 274.

Also provided in FTRD modular device 210 is a stapler hammer 280.Stapler hammer 280 inserts staples 278 into the clamped tissue. Staplerhammer 280 is spring loaded and actuated by manual release of the spring282. A manual release trigger is controlled by the operator throughmanipulation of an actuator external to the patient to actuate thestapler hammer 280 to insert staples 278 into the tissue. Spring 282 maybe actuated, for example, when released via a mechanical cable from acompressed state. As would be understood by those of skill in the art,although element 282 is shown as a spring, other devices such as theactuators previously described may be used. Alternatively, instead of orin addition to the FTRD modular device 210, other devices such ascutters, tissue cauterizing devices, graspers, biopsy devices, etc., maybe contained within the modular device 210. Additionally, the device maybe actuated by other means such as remote control or under computercontrol.

A preferred method of using an endoluminal modular access deviceaccording to one embodiment of the present invention will now bedescribed with reference to FIGS. 5A-5D. First, a guide track 120 b isselected and inserted by the operator into a body lumen 103 of thepatient's body. Selection of an appropriate guide track 120 b may dependon the size and characteristics of the body lumen, the correspondingsize of the modular device 110, the types of tools contained within themodular device 110 and/or required for the particular procedure to beperformed and which would effect the weight of the modular device 110,and the characteristics of the power source being used to drive themodular device 110 along the track 120 b. After the guide track 120 bhas been inserted into the modular device 110, a distal end of the guidetrack 120 b is advanced to the treatment site and anchored to a desiredlocation at or near the treatment site as would be understood by thoseof skill in the art. For example, an anchor module 150 may be placed onthe guide track 120 b and advanced by actuation of, for example, a servoscrew motor within the anchor module 150. The anchor module 150 may thenbe advanced to the distal end of the guide track 120 b and, at thispoint, an extendible member 152 is expanded, e.g., by supplyinginflation fluid to a tube 156 to inflate an anchoring balloon of theextendible member 152 thereby anchoring the guide track 120 b at thedesired position within the body lumen 103. Those skilled in the artwill understand that the modular device 110 need not be coupled to theguide track 120 b before the distal end thereof is anchored at thedesired location. Alternatively, after the distal end of the guide track120 b has been anchored in place, the modular device 110 may be advancedover the proximal end of the guide track 120 b into the body lumen 103.

Once guide track 120 b has been anchored within body lumen 103, modulardevice 110 is attached to guide track 120 b at the proximal end of guidetrack 120 b external to the patient. Modular device 110 is then advancedalong guide track 120 b toward the distal end thereof and is positionedwithin the body lumen 103. If desired, when the device has reached adesired position within the body lumen 103, the extendible member 154may be deployed by an operator, e.g., by introducing fluid to the tube156 which extends to the extendible member 154, in order to push modulardevice 110 into a position adjacent the wall of lumen 103.

For example, in the case of the FTRD modular device 210, a window isprovided in the outer casing 202 of FTRD modular device 210 throughwhich a grabbing element 260 and grippers 262 may be extended to graband retrieve a selected portion of tissue when the clamping element 274has been moved to an open position away from the window. The selectedtissue sample is then pulled into the tissue receiving chamber 264 a(i.e., the space between the anvil 264 and the clamping element 274). Asdescribed above, once the selected tissue sample has been drawn into thetissue receiving chamber 264 a, the actuator 276 is operated to move theclamping element 274 into the closed position clamping the tissueagainst the anvil 264. When clamped into the tissue receiving chamber264 a, the selected portion of tissue should be folded over so that aportion of tissue twice the thickness of the organ is clamped betweenthe clamping element 274 and the anvil 264 (i.e., the clamping element274 contacts an inner surface of a first portion of the wall of theorgan with an outer surface of the first portion of the organ contactingan outer surface of a second portion of the organ and an inner surfaceof the second portion of the organ contacts the anvil 264. The gripper262 may then be released and withdrawn. The hammer 280 is then operatedto drive staples through the full thickness of the tissue of the firstand second portions of the organ with the staples being formed againstthe anvil 264. After completing the stapling, the cutter element 266 isactuated and begins rotating through the selected portion of tissue tocut this tissue from the wall of the body lumen 103. Because the fullthickness of the tissue of the first and second portions of the organhas been stapled together, cutting away that portion of tissue receivedradially within the stapled portion leaves the organ sealed. After thecutting has been completed, the extendible member 154 is deflated, andthe FTRD modular device 210 is driven in reverse (i.e., proximally)along guide track 120 b toward the external opening of the lumen. Whenthe FTRD modular device 210 has been removed from the body lumen 103,the extendible member 152 is deflated, and the anchor module 150 is alsodriven along guide track 120 b proximally to the external opening of thebody lumen 103. Once the extendible member 152 has been removed from thebody lumen 103, the guide track 120 b is withdrawn therefrom by theoperator, and if necessary, the external opening to the body lumen 103is surgically closed.

Alternatively, as shown in FIGS. 6A, 6B and 6C and described furtherherein, an alternate drive mechanism including a drive-shaft 320 whichextends from the modular device 110 through the body lumen and out ofthe body where it may be coupled to a power source (not shown). Thoseskilled in the art will understand that the modular device 110 accordingto this embodiment may be substantially similar to those of thepreviously described embodiments, except that no motor or other powersource is located therewithin. Rather, motive power is transmitted tothe modular device from the external power source via the drive shaft320. The drive shaft 320 extends into the modular and couples to a drivemechanism (not shown) which may be constructed in accord with any of thepreviously described embodiments. Specifically, the drive shaft 320includes a thick outer shell 321 with an inner gear 322 being rotatablewithin the outer shell 321 when driven by the external power source. Theouter shell 321 is removed from a distal end of the drive shaft 320 toexpose the inner gear 322 so that the inner gear may engage the drivemechanism. As would be understood by those of skill in the art, themodular device 110 may further include a slip clutch and a cable whichconnects to the drive shaft 320 or other suitable drive mechanism tomove modular device 110 along the guide track 120 as the drive shaft 320is rotated.

Those skilled in the art will understand that the described exemplaryembodiments of the invention may be altered without departing from theteaching of the invention, e.g., by replacing the spring actuation ofthe stapler or the linear transducer actuators described bypneumatically actuated mechanisms. Thus, it is to be understood thatthese embodiments have been described in an exemplary manner and are notintended to limit the scope of this invention which is intended tocovers all modifications and variations of this invention that comewithin the scope of the appended claims and their equivalents.

1. An endoluminal access system for accessing a body lumen, comprising:a guide track which, when in an operative position, extends through abody lumen to a desired location therewithin; and a modular deviceselectively coupleable to the guide track, the modular device includinga drive mechanism for engaging the guide track to move the modulardevice along the guide track within the body lumen.
 2. The system ofclaim 1, wherein the guide track includes one of a catheter and a guidewire.
 3. The system of claim 1, wherein the guide track includes asubstantially helical contact surface formed on an outer surface thereofand wherein the drive mechanism engages the contact surface to move themodular device along the guide track.
 4. The system of claim 1, whereinthe drive mechanism includes a motor located within the modular device.5. The system of claim 4, wherein the motor is an electric motor andwherein the drive mechanism includes a cable extending out of themodular device to an external power source.
 6. The system of claim 1,wherein the drive mechanism includes a threaded member for engaging thecontact surface and rotating about the guide track.
 7. The system ofclaim 1, wherein the modular device includes a guide track receivinglumen extending therethrough for receiving the guide track therein. 8.The system of claim 1, wherein the drive mechanism includes gearsmoveable between an engaging position for engaging the guide track tomove the modular device therealong and a retracted position separatedfrom the guide track.
 9. The system of claim 1, further including ananchoring module moveable along the guide track for anchoring the guidetrack at a desired location within the body lumen.
 10. The system ofclaim 9, wherein the anchoring module includes a first extendible membermoveable between a retracted position in which the anchoring module isfree to move within the body lumen and an extended position in which thefirst extendible member contacts a wall of the body lumen to anchor theguide track in a desired position therewithin.
 11. The system of claim10, wherein the first extendible member includes a first balloon, thesystem further comprising a first inflation lumen extending between aninlet which remains outside the patient's body to an outlet coupled tothe first balloon.
 12. The system of claim 1, further comprising asecond extendible member coupled to the modular device, the secondextendible member being moveable between a retracted position in whichthe modular device is free to move within the body lumen and an extendedposition in which the second extendible member contacts a wall of thebody lumen to anchor the modular device at a desired positiontherewithin.
 13. The system of claim 12, wherein the second extendiblemember includes a second balloon, the system further comprising a secondinflation lumen extending between an inlet which remains outside thepatient's body to an outlet coupled to the second balloon.
 14. A modulardevice for tissue resection comprising: a housing including a guidetrack receiving lumen extending therethrough; a motor mounted within thehousing, the motor being selectively engageable with a guide trackreceived within the guide track lumen to move the modular devicetherealong; a tissue receiving chamber formed within the housing; agrabbing mechanism for drawing a selected portion of tissue into thetissue receiving chamber; a resection mechanism for resecting theselected portion of tissue.
 15. The system of claim 14, furthercomprising a stapling mechanism for stapling a portion of tissueadjacent to the selected portion of tissue.
 16. The system of claim 14,wherein the housing includes a window moveable between an open positionin which the tissue receiving chamber is exposed to an exterior of thehousing and a closed position in which the tissue receiving chamber issubstantially closed.
 17. The system of claim 14, wherein the motor isan electric motor including a sleeve armature extending around the guidetrack receiving lumen.
 18. The device of claim 14, wherein the grabbingmechanism include opposable arms which may be extended to grasp theselected portion of tissue and retracted to draw the selected portion oftissue into the tissue receiving chamber.
 19. The device of claim 14,wherein the grabbing mechanism includes a vacuum port for supplyingnegative pressure to draw the selected portion of tissue into the tissuereceiving chamber.
 20. The device of claim 14, wherein the motor iscoupled to at least one roller gear moveable between an engagementposition in which the at least one roller gear is positioned adjacent tothe guide track receiving lumen to engage a guide track received thereinand a retracted position in which the roller gear is separated from theguide track receiving lumen.
 21. The device of claim 20, wherein the atleast one roller gear includes a first set of roller gears positionedadjacent to a proximal end of the guide track receiving lumen and asecond set of roller gears positioned adjacent to a distal end of theguide track receiving lumen.
 22. A method of resecting tissue from asite within a body comprising the steps of: inserting a guide track to adesired location within the body lumen; coupling a modular device to aproximal end of the guide track; actuating a motor mounted within themodular device to drive the modular device distally along the guidetrack to the site; drawing tissue at the site into the modular device;coupling together a portion of tissue adjacent to the site; resectingthe tissue from the site; and actuating the motor to drive the modulardevice proximally to withdraw the modular device from the body lumen.23. The method of claim 22, further comprising the step of anchoring theguide track at the desired location.
 24. The method of claim 23, whereinthe step of anchoring the guide track further comprises the sub-stepsof: mounting an anchoring module on the guide track; moving theanchoring module along the guide track to an anchoring location; andextending an anchoring member of the anchoring module to anchor theanchoring module at the anchoring location thereby anchoring the guidetrack at the desired location.
 25. The method of claim 22, furthercomprising the step of extending a positioning member from the modulardevice to maintain the modular device in a desired position within thebody lumen.